4 ideas
7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
4871 | A thing is free if it acts only by the necessity of its own nature [Spinoza] |
7667 | There are two sides to men - the pleasantly social, and the violent and creative [Diderot, by Berlin] |